The present invention relates to a production line for manufacturing disposable absorbent articles from bulk starting polymeric materials including virgin and on-line recycled polymeric materials.
Disposable absorbent articles are often produced on high-speed converting lines using, for starting materials, continuous webs of fabrics, films, foams, elastics, etc. that have been transported from web producers in a packaged form (e.g., as wound rolls or festooned boxes), and are unpacked (e.g., unwound or de-festooned) in order to be fed as continuous webs into the converting line. In the converting lines, various converting operations work the webs to convert them into components of disposable absorbent articles that are eventually joined into a composite web that is finally cut into discrete final articles.
Unfortunately, packing and transporting continuous webs presents several problems. First, packing and transporting can often irreversibly change the web material, especially the webs that need to retain original, pre-packaged properties. For example, a soft, high-loft web can become continuously flat as a result of roll winding or intermittently deformed as a result of festooning. (When wound into a roll, the web is subjected to compression forces that are often needed for both retaining the web in the roll formation and for subsequent un-winding of the web from the roll. Also, when packaged in a festoon configuration into a box, the web often develops a permanent creep in the folded portions of the festooned web due to being bent and compressed.) Second, webs often need to be provided with special strength properties to make them suitable for roll winding or festooning. These properties often are achieved by applying to these webs special additives that can affect or compromise the desired properties of the final product and/or increase the cost of the web. Similar negative effects can take place when, prior to roll winding, the webs are sprayed with anti-static solutions to prevent or minimize in-layer subsequent sticking during un-winding of the web. Third, webs often require relatively expensive winding and un-winding high-speed automatic equipment and qualified personnel to operate and support it. Fourth, often the material properties that cannot be provided by a packaged web need to be provided by converting operations specially developed to make the web softer, thinner, thicker, elastic, absorbent, cloth-like, breathable, aesthetic, etc. These operations add more cost and time in developing new products.
Consequently, it would be beneficial to reduce or eliminate the need for packing and transporting of the webs to the product converting lines by providing a new process which is continuous from the material-forming operations to the product-converting operations. Further, because the web-forming operations need to run continuously without interruptions in order to prevent solidification of molted polymeric materials inside of the web-forming equipment, and the product-converting operations may have interruptions or production outages due to various malfunctions, it would be beneficial for the new process to recycle the polymeric materials produced by the web-forming operations during the production outages. It would be further beneficial to re-use the recycled materials in the new process.
In response to the difficulties and problems discussed above, a new production line for manufacturing disposable absorbent articles has been discovered that can reduce or eliminate the need for packaged webs. The production line includes a continuous process that links the web-forming operations, specifically nonwoven-web forming operations, with the product-converting operations. The production line utilizes bulk starting polymeric materials, both virgin polymeric materials and polymeric materials recycled and on the production line to be re-used on the production line in production of disposable absorbent articles. The production line can be a single-product lane operation or a multiple-product lane operation.
In one aspect, the present invention concerns a production line that extrudes polymeric materials and forms individual components from the extruded materials, such as a liquid previous topsheet, a liquid impervious backsheet and an absorbent core disposed therebetween. The production line includes a moving surface to move a web of material through the production line; a backsheet station adjacent the moving surface to form the backsheet by extruding a first polymeric material, provided to the backsheet station as a first starting material, onto the moving surface; a core station adjacent the moving surface to form the absorbent core by extruding a second polymeric material, provided to the core station as a second starting material, onto the moving surface; and a topsheet station adjacent the moving surface to form the topsheet by extruding a third polymeric material, provided to the topsheet station as a third starting material, onto the moving surface.
The production line further includes one or more cutting devices adjacent the moving surface to cut a trim and to form lateral configurations of the topsheet and the backsheet. The production line further includes a first recycling station for collecting and recycling the trim into the first recycled material and a second recycling station for collecting and recycling non-woven materials of the topsheet, the backsheet or the absorbent core collected during an outage of the production line into a second recycled material. The production line further includes one or more bonding modules adjacent the moving surface to provide the second recycled material for bonding the backsheet, the topsheet and the absorbent core to each other.
In another aspect, the present invention concerns a production line that extrudes and forms the topsheet and the backsheet from the extruded polymeric materials and combines these components with an absorbent core produced off the production line and provided to the production line as a continuous web or discrete objects. The production line further includes one or more cutting devices adjacent the moving surface to cut a trim and to form lateral configurations of the topsheet and the backsheet. The production line further includes a recycling station for collecting and recycling the trim and non-woven materials of the topsheet or the backsheet into a recycled material. The production line further includes one or more bonding modules adjacent the moving surface to provide the recycled material for bonding the backsheet, the topsheet and the absorbent core to each other.
In another aspect, the present invention concerns a method for recycling continuous fibers exiting one or more spun-bonded modules during an outage of the production line. The method includes the following steps: (a) providing at least one spun-bonded module; (b) diverging the continuous fibers exiting the spun-bonded module into a recycling operation by a gust of a compressed fluid; (c) disintegrating the continuous fibers in the recycling operation; (d) conveying the disintegrated fibers into a recycling station; and (e) recycling the disintegrated fibers into a recycled polymeric material.
In another aspect, the present invention concerns a method for recycling a molten polymeric material exiting a spinneret of a melt-blown module back in the melt-blown module, the method includes the following steps: (a) providing the melt-blown module extruding the molten material; (b) providing a collecting die for collecting the molten polymeric material from the spinneret; (c) providing a conduit being in communication with the collecting die for transporting the molten polymeric material; (d) collecting the molten polymeric material exiting the spinneret by the collecting die; and (e) transporting the molten polymeric material by the conduit from the collecting die to a metering pump of the melt-blown module for re-extruding the molten polymeric material through the spinneret.